The BGS Lexicon of Named Rock Units — Result Details

Chapel House Limestone Formation

Computer Code: CHPL Preferred Map Code: notEntered
Status Code: Full
Age range: Arundian Substage (CJ) — Arundian Substage (CJ)
Lithological Description: The lower part of succession is dominated by mid to mid-pale grey, medium- and coarse-grained calcarenite, oolitic grainstones interbedded with conglomerates, "mixed laminates" (ie. interbedded siltstone with sandstone and mudstone laminae), dolomicrites and fenestral or algal lime-mudstones. Argillaceous wackestones occur locally in the upper part of the formation.
Definition of Lower Boundary: Drawn at base of conglomerate of the Chapel House Limestone Formation where it rests with significant non-sequence on the deeply fissured limestone top surface to the Stockdale Farm Formation, which comprises limestone, siltstone and mudstone. It lies directly on Lower Palaeozoic rocks elsewhere.
Definition of Upper Boundary: Drawn at sharp conformable upward passage from grainstone of the Chapel House Limestone Formation to darker limestones of the Scalebar Force Limestone Member (Kilnsey Formation).
Thickness: Maximum of about 56m adjacent to the Middle Craven Fault, with 33.6m in the type section.
Geographical Limits: A series of inliers in the southernpart of the Askrigg Block, North Yorkshire, including Gordale Beck (SD 91 65), Stainforth Force on the River Ribble (SD 82 67) and Barrel Sykes, north of Settle (SD 82 64). Proved elsewhere in the subsurface of the Settle area in boreholes.
Parent Unit: Great Scar Limestone Group (GSCL)
Previous Name(s): none recorded or not applicable
Alternative Name(s): none recorded or not applicable
Stratotypes:
Type Section  Chapel House Borehole, near Kilnsey, Yorkshire, records the entire thickness (33.8m) of the Formation from 90.12m (base) to 56.3m (top). Arthurton et al. 1988. 
Reference(s):
Arthurton, R S, Johnson, E W, and Mundy, D J C. 1988. Geology of the country around Settle. Memoir of the British Geological Survey, Sheet 60 (England and Wales). 
Murray, D W. 1983. The limestone and dolomite resources of the country around Settle and Malham, North Yorkshire (with notes on hard-rock resources of Horton-in-Ribblesdale area). Description of parts of Sheets 50 and 60. Mineral Assessment Report of the Institute of Geological Sciences, No.126. 31pp. 
1:50K maps on which the lithostratigraphical unit is found, and map code used:
E060